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1.
Angela B. Lange Ian Orchard Vicki A. Te Brugge 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,168(3):383-391
Summary The presence of a SchistoFLRFamide-like peptide associated with the oviducts of Locusta migratoria has been shown using sequential reversed-phase high performance liquid chromatography separation coupled with radioimmunoassay and bioassay. The peptide is present in areas of the oviduct which receive extensive innervation, with sixfold less peptide in areas that receive little innervation. Material with FMRFamide-like immunoreactivity (determined by radioimmunoassay) is also present in the oviducal nerve and VIIth abdominal ganglion.SchistoFLRFamide is a potent modulator of contraction of this visceral muscle, inhibiting or reducing the amplitude and frequency of spontaneous contractions, relaxing basal tonus, and reducing the amplitude of neurally-evoked, proctolin-induced, glutamate-induced and high potassium-induced contractions. The FMRFamide-like immunoreactivity within the oviducts which co-elutes with SchistoFLRFamide on two separations is also capable of reducing the amplitude of neurally-evoked and proctolin-induced contractions, and of inhibiting spontaneous contractions and relaxing basal tonus.The effects of SchistoFLRFamide upon this visceral muscle are not abolished by the -adrenergic receptor antagonist phentolamine and do not appear to be mediated by cyclic AMP. Thus the receptors for Schisto-FLRFamide are distinct from those of octopamine which mediate similar physiological effects but which are blocked by phentolamine and which are coupled to adenylate cyclase.The results indicate that SchistoFLRFamide, or a very similar peptide, which has previously been identified as a modulator of locust heart beat, is also associated with visceral muscle of the reproductive system, and may play a neural role in concert with octopamine, at modulating muscular activity.Abbreviations
BPP
Bovine pancreatic polypeptide
-
BSA
Bovine serum albumin
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EJP
Excitatory junctional potential
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FaRPs
FMRFamide-related peptides
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FLI
FMRFamide-like immuno-reactivity
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LMS
Leucomyosuppressin
-
RIA
Radioimmunoassay
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RP-HPLC
Reversed-phase high performance liquid chromatography
-
TFA
Trifluoroacetic acid 相似文献
2.
Tai Te Wu 《Bulletin of mathematical biology》1969,31(2):395-402
In view of the possible changes of the structure of DNA at different relative humidities, a similar model for tRNA is proposed. In the native form, the sugar phosphate backbone folds repeatedly on itself resulting in a circular rod structure of about 50 Å in length and about 25 Å in diameter. Both the amino-acyl end and the anticodon site are surrounded by segments of base sequences common to different tRNA’s. 相似文献
3.
Tai Te Wu 《Bulletin of mathematical biology》1968,30(4):687-700
The conformation of a deoxyribonucleotide unit in a deoxyribonucleic acid molecule can be defined by six angles, each of which
specifies the relative orientations between two groups of atoms adjacent to a covalent bond. With the assumption that these
atoms are hard spheres with fixed van der Waal radii, conformations are sought to minimize their overlapping. The additional
requirement of the polymer having a periodic structure further reduces the allowable conformations. 相似文献
4.
Xue-Fan Gu Felix de Rooij J. S. Lee Kor Te Velde Jean Charles Deybach Yves Nordmann Bernard Grandchamp 《Human genetics》1993,91(2):128-130
Acute intermittent porphyria (AIP) is an autosomal dominant disease characterized by a deficiency of porphobilinogen deaminase (PBGD). Up to now 14 different mutations have been described. In an effort to investigate the molecular epidemiology of AIP we have undertaken a systematic study of different exons of the PBGD gene from a large number of unrelated patients. Here, exon 8 from 82 unrelated Dutch and French AIP patients was examined using single strand confirmation polymorphism analysis (SSCP) after polymerase chain reaction (PCR) amplification. A single base mutation, C to T, at position 346 of the sequence coding for PBGD was observed in 15 Dutch families but in only 1 French family. A simple PCR assay is described to facilitate the diagnosis of this common mutation at the DNA level. 相似文献
5.
6.
T-cell receptor (Tcr) chains are classified into four subgroups (I, II, III, and miscellaneous) based on the amino acid residues at positions 61 and 62. Subgroup I has Gly Phe at these positions, subgroup II has Arg Phe, subgroup III has Arg Leu, and subgroup miscellaneous has several other combinations. Variability plots for subgroups I, II, and III sequences show higher values around positions 93–103, 105, 108, 111, 113, and 115, suggesting that these positions may interact with the processed antigen molecules. Smaller peaks are present at various other regions which may bind the major histocompatibility complex class I or II molecules. The patterns of variability within one subgroup are similar for all species, for human alone, and for mouse alone. These subgroup patterns appear much less complicated than patterns for sequences in all subgroups taken together, implying that subgroups may be related to Tcr functions. Among 83 mouse chains, 15 are from cytotoxic cells and 40 from helper cells. Of the 15 from cytotoxic cells, 11, 2, 0, and 2 are in subgroups I, II, III, and miscellaneous; and of the 40 from helper cells, 9, 16, 12, ans 3 are in subgroups I, II, III, and miscellaneous, respectively. Thus, a correlation between sequence and function of Tcr chains seems possible.
Address correspondence and offprint requests to: M. Schiffer. 相似文献
7.
The protective effect of pig immune colostrum, serum and immunoglobulins IgG, IgM and IgA against the enterotoxic strain ofEscherichia coli O55, was studied in newborn germfree piglets. This strain produced accumulation of fluid and dilatation of intestine when
injected into the ligated ileal segment of germfree piglets, which is considered to be the typical effect of enterotoxins.
Erosion of the intestinal epithelium and penetration of bacteria into the submucosa were also observed. Immune serum, colostrum
and all the immunoglobulin classes used produced a local protective effect, IgA being most effective. The mechanism of protection
conferred by these immunoglobulins is discussed with respect to the possible pathogenic action of enterotoxicEscherichia coli O55 in the intestinal tract of immunologically virgin germfree piglets. 相似文献
8.
9.
调水工程引起的多环境因子关联变化对沉水植物群落的影响机制有待深入探讨。以南水北调东线工程调蓄河湖群中菹草种群为研究对象,分析了京杭运河(YH)、高邮湖(GY)、洪泽湖(HZ)、骆马湖(LM)、南四湖上级湖(NS1)、南四湖下级湖(NS2)和东平湖(DP)7个调蓄河湖中菹草个体功能性状特征及其与环境因子间的关系。结果表明:(1)除高锰酸盐指数(COD_(Mn))、浊度(Tur)和底泥有机质含量(S_o)外,总氮(TN)、硝氮(NO_3-N)、氨氮(NH_4-N)、总磷(TP)、正磷酸盐(PO_4-P)、硅酸盐(SiO_4-Si)、叶绿素a(Chla)、总溶解性固体(TDS)、透明度(SD)、消光系数(K)、水温(T)、电导率(Cond)、酸碱度(pH)、溶解氧(DO)和底泥含水率(S_w)在河湖间差异达到了极显著水平;(2)菹草株高、茎分支数、茎节数、茎节长、茎直径、相对茎长、叶片数、叶厚、叶长、叶宽、叶面积、比叶面积、株重、茎重、叶重、茎叶比、茎干物质比、叶干物质比在河湖间差异极显著;(3)河湖群内菹草种群18个功能性状中,按变异系数从小到大依次为:叶宽、茎直径、叶长、茎干物质比、叶干物质比、叶面积、株高、茎节长、相对茎长、茎叶比、叶厚、茎节数、茎重、叶片数、株重、比叶面积、叶重、茎分支数;7个调蓄河湖间,按照所有性状变异系数平均值从大到小排序依次为:南四湖下级湖、洪泽湖和京杭运河、高邮湖、东平湖、南四湖上级湖、骆马湖;(4)环境因子共解释了功能性状方差变异的49.43%;叶性状主要受营养因子(TN、NO_3-N、SiO_4-Si)影响;茎性状与光照因子(Chla和SD)密切相关;底泥因子(S_o)对茎叶生物量分配起主要作用。 相似文献
10.
Philp Joshua Neil Monty Cornish Peter S. Te Kim Sok Heng Bell Richard W. Vance Wendy Lim Vanndy Li Xueling Kamphayae Sukanya Denton Matthew D. 《Plant and Soil》2021,461(1-2):617-630
Plant and Soil - Perennial forage grass production has the potential to improve smallholder livelihoods in the tropics. However, nutrient management is often challenging, especially on infertile... 相似文献